A. Field of the Invention
This invention relates to a machine to automatically cut-off one end of a hollow glassware article and, more specifically, to an intermittent rotary machine to rotary grip the first cut-off opened end of a tubular article and cut-off the second end thereof.
B. Description of the Related Art
In the production of seamless hollow tubular glassware articles such as glass tubes for oil lamps, produced by the press-and-blow process in the so known paste molds, the glassware articles are produced firstly as a parison having a closed bottom and an opened neck which is gripped by a rotary neck ring and rotated within the paste mold to blow a seamless semi-finished article.
Said semi-finished article having therefor a leftover or excess section at its opened neck end corresponding to the section which was gripped by the neck ring of the forming machine, as well as a closed bottom end which allowed the article to be blown and shaped, both of which sections have to be cut-off and fire finished to produce a tubular glassware article open at by both of its ends.
There is a well known Japanese continuously rotary automatic machine to cut-off the leftover section of the opened neck end of said tubular glassware article.
Said continuously rotary automatic machine includes a lower continuously rotary table having twelve two-halves annular burners formed by two semi-annular pieces which are opened and closed around a leftover section of the article to cut it off and fire finish it while rotating around the machine; and an upper continuously rotary table having twelve suction cups equally mounted thereon, each suction cup grips an article necessarily by its closed bottom end at a charging position, lowering and continuously rotating the article to place the leftover section of its opened neck end on a position wherein a corresponding burner closes around it to be cut-off while rotating in said suction cup and around the machine, and finally lifting and stopping the rotation of the article, once the leftover section has been cut-off, to leave it at a discharging position.
The continuous rotation of this machine is provided by a continuously rotary motor which in turn transmits its continuous rotary movement to the chucks through a clutching mechanism traveling in said rotary machine and geared to a stationary chain.
Because of the suction cups of the above disclosed machine, the article necessarily has to be gripped by its closed bottom end to allow the suction gripping action thereon, it in turn to cut-off the leftover section of the opened neck end of the article.
Therefore, said machine is not useful to cut-off the closed bottom end of the article because the suction cups cannot grip the opened neck end thereof.
Consequently, in the previous art, it was necessary to provide at least three semi-automatic cut-off machines each having two cut-off stations, to grip the cuto-ff opened neck end of the article and cut-off the closed bottom end thereof.
Each of said cut-off stations including a two-halves annular burner which is hand-closed by the operator when receiving an article and hand-opened once the closed bottom of the article has been cut-off and fire finished; a chuck having hand-operating fingers which are hand-opened by the operator by means of an actuator to receive and grip the opened neck of the article; and a continuously rotary clutching mechanism to clutch said chuck imparting it the necessarily continuous rotary motion and allow the closed bottom end of the article to be cutoff and fire finished.
During these operations, the operator carefully places the article in a vertical position maintaining a relative eccentricity of the article in relationship with the burner, to obtain the correct cut off the angle within the specifications.
The reliability of these adjustments wholly depended on the ability of the operator because the machine has no sizing tools.
The disadvantages of the Japanese continuously rotary machine are mainly that, as the machine is continuously rotating, it has no time to properly charge an article in a right position regarding the suction cup, consequently providing a cut-off which is not absolutely perpendicular to the central axes of the article.
Regarding the disadvantages of the manual cut-off machines to make the second cut-off (of the closed bottom end) of the article, the manual charge of the article by the operator to the suction cups, causes an unreliable position the perpendicular with the central axis of the article and in its rotation, resulting in cut-off irregularities such as undulations.
Furthermore, the time of the cut-off and fire finishing depend on the ability of the operator, resulting in edges of different width affecting the size and verticality of the article.
The absence of automatic means to control the cut-off and fire finishing cycles caused also a great loss of gaseous fuel and energy.
All of these disadvantages caused the impossibility to continuously process all the tubular glassware articles produced by the forming machine, in fact these machines could cut-off only about 40% of the produced articles being necessary to have about a 60% backlog of articles in stock, to be processed in an additional time.
Additionally, the manual charge and processing of the articles, causes a great loss of product reaching about 30% of the produced articles.
Last but not least, another disadvantage of the manual machines is the number of skilled required to handle the machines which were about 10 on each working period.
The machine to automatically cut-off one end of a hollow glassware article, in accordance with the present invention, overcomes all of those disadvantages of the prior art machines, because it is absolutely automatic and can be used to cut-off both ends of the articles, and comprises: a support structure including a shaft; an intermittent rotary driving mechanism mounted on the shaft, a plurality of positions corresponding to article charging, cut-off, fire finishing and discharge positions; a lower intermittent rotary table mounted on said shaft and rotary coupled to the intermittent rotary driving mechanism, including a plurality of burners equally distributed on its periphery, to cut-off a leftover piece at a lower end of the article and fire finishing the cut-off end thereof within a cut-off cycle; an upper intermittent rotary table coupled to said lower table, comprising a plurality of chuck supporting and actuating mechanisms, equally mounted thereon, each including a chuck having fingers to grip an upper end of the article at a charging position, bring down the gripped article at a cut-off position placing its leftover piece in a burner to be cut-off and fire finished and lift and discharge the finished article at a discharge position; and a continuously rotary driving mechanism to rotate the chuck and article gripped thereby through the cut-off and fire finishing positions.
Furthermore, because of its intermittent rotary movement, the quality and production volumes are greatly increased, allowing to process substantially all the glassware production of the forming machine without backlog.